Owing to development of science and technology, applications of wireless communication technologies have become increasingly widespread. Many of the wireless communication technologies, such as those adopting GSM (Global System for Mobile Communications), WCDMA (Wideband Code Division Multiple Access), GPRS (General Packet Radio Service), PHS (General Packet Radio Service), WiFi (Wireless Fidelity), WiMAX (Worldwide Interoperability for Microwave Access) or LTE (Long Term Evolution), rely on a base station (BS) to provide wireless voice, image, data communication and mobile device positioning services.
For wireless communication systems, whether they adopt the WiMAX or the LTE wireless communication technology, BSs thereof are typically deployed on the basis of the cellular communication concept and designed with a high power level and large communication coverage. However, although macro BSs have already been deployed at a considerably high density, most indoor environments still suffer from degradation in wireless communication quality due to the shadow effect of buildings; and the shadow effect of buildings may even result in coverage holes that cause failure of service providers to provide services effectively.
In order to reduce the coverage holes, improve the system capacity and make more efficient use of the wireless bandwidth resources of the wireless communication system, more concerns have been gradually put on Femtocell BSs in addition to the original deployment of the macro BSs, and the Femtocell BS technology has been considered as one of the key technologies for the next generation of wireless communication. Albeit of the smaller signal coverage of the Femtocell BSs as compared to the macro BSs, the Femtocell BSs have advantages of a low power level and low production cost, so they can be widely deployed in indoor environments to improve the wireless communication quality. Additionally, in the wireless network systems, the bandwidth originally allocated to the macro BSs may also be re-allocated to individual Femtocell BSs to improve the bandwidth efficiency of the wireless communication system.
However, in a wireless communication system, a mobile device can perform data transmission with only a single BS at a given time point; and during the data transmission, it is possible that the connection between the mobile device and the BS is interrupted if the BS ceases providing the services or suffers from interference. In either case, consequently, the mobile device has to find another BS and perform a network entry procedure with the another BS again in order to recover the data transmission; this will cause discontinuity of the data transmission between the mobile device and the BS and also delay in the data transmission.
Accordingly, efforts still have to be made by wireless communication network providers and wireless communication device manufacturers to address the desire of the general public for a solution that can reduce or obviate data transmission discontinuity and/or delay due to interruption of a connection between the mobile device and the BS without modifying the hardware architecture of the existing wireless communication systems.